ADVANCES
20 Scientific American, February 2022Mauritius Images GmbH/Alamy Stock PhotoEvery April for the past decade, systems biologist
Rodrigo Gutiérrez has driven 1,600 kilometers (1,000
miles) to reach one of the driest places on Earth: Chile’s
Atacama Desert, parts of which receive less than three
millimeters of rain annually. His team collected plants
and soil from nearly two dozen sites each year, froze the
samples in liquid nitrogen, and brought them back to his
laboratory at the Pontifical Catholic University of Chile.
For a new study in the Proceedings of the National Acad-
emy of Sciences USA, Guitérrez and his colleagues ana-
lyzed the plants’ genes and the microorganisms that
help them thrive in such extreme conditions.
“We knew almost nothing about how these plants
survived,” Gutiérrez says. “There was great potential
to study these wild species, which is now a little easier
with all the genomic tools that we have.” His team inves-
tigated 32 plant species, some closely related to grains,
legumes and potato crops, from three altitude ranges.
Scientists usually conduct genetic studies on lab-
grown plants, which lets researchers tightly control fac-
tors such as the amount of nutrients and light the plants
receive. But sampling plants in nature captures critical
differences based on their varied living conditions. This
study “merges the genomics with ecological under-
standing of how plants behave in their natural environ-
ment,” says University of California, Davis, plant biolo-
gist Neelima Sinha, who was not involved in the
research. “That just by itself makes it very significant.”
To identify genes that contribute to the plants’ sur-
vival, Gutiérrez worked with ecologists, plant biologists,
genomics experts and computer scientists to compare
the genetic codes of the sampled Atacama species with
those of closely related plants. In what the researchers
describe as a “genetic gold mine,” they traced genomes’
evolutionary changes and identified adaptive mutations
related to stress response, metabolism and energy pro-
duction. These mutations might help desert plants tol-
erate intense solar radiation, optimize water capture
and adjust flowering times. The researchers also discov-
ered an abundance of bacteria that live on the desert
plants’ roots and convert nitrogen from the air into a
usable form, aiding growth in nitrogen-poor soils.
Researchers could potentially insert newfound genes
into food plants and grasses used for biofuel, Gutiérrez
says, giving such species better survival odds when
planted in saltier soils and areas experiencing drought—
conditions expected to become more severe with
climate change.
G E N E T I C SScience
in Images
By Susan Cosier
To see more, visit ScientificAmerican.com/science-in-images